Do i just plug in ? i’m confused

Yes, plug them in. 5) (23/2) or 11.5      6) 51

Step-by-step explanation:

Since you're simply finding the functions, yes you plug in the variables directly.  

5) f(x) = 10 - (9 / 2) * x

   f(-(1/3)) = 10 - (9 / 2) * -(1/3)

                = (23/2) or 11.5

6) g(20) = |-3 * (20) + 16|

             = |-44|

             = 44

   h(7) = -(7)^2 + 8 * (7)

          = 7

   g(20) + h(7) = 44 + 7

          = 51

its adding 5.5 each time

step-by-step explanation: